/**************************************************************************
 *
 * Copyright (C) 2007 University of California, Los Angeles.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 *************************************************************************/

package edu.ucla.cs.typecast.event;

import java.io.*;
import java.net.InetAddress;
import java.util.Hashtable;

import edu.ucla.cs.typecast.net.EndPoint;
import edu.ucla.cs.typecast.net.EndPointListener;
import edu.ucla.cs.typecast.net.EndPointListenerFactory;
import edu.ucla.cs.typecast.net.TypeCastConstants;

/**
 * Factory that creates event sources and event sinks.
 */

public class EventManager {
	private static EventManager instance = new EventManager(); 
	
	public static EventManager getInstance() { 
		return instance; 
	}
	
	private Hashtable<EndPoint, EventDispatcher> dispatchers = new Hashtable<EndPoint, EventDispatcher>(); 

	public EventSink getEventSink(Class type ) throws IOException  { 
		return getEventSink(new Class[] { type }); 
	}

	public EventSink getEventSink(Class[] types) throws IOException  { 
		return getEventSink(InetAddress.getByName(TypeCastConstants.DEFAULT_EVENT_ADDRESS), TypeCastConstants.DEFAULT_EVENT_PORT, types); 
	}
	
	/**
	 * Create a EventSink that can receiv event of specific types.
	 * 
	 * @param types
	 *            The types that this EventSink should support.
	 * @return
	 */
	public synchronized EventSink getEventSink(InetAddress addr, int port, Class[] types) throws IOException  { 
		EndPoint endPoint = new EndPoint(addr, port); 
		EventDispatcher dispatcher = dispatchers.get(endPoint); 
		if (dispatcher == null) {
			EndPointListener endPointListener = EndPointListenerFactory.createEndPointListener(endPoint); 
			dispatcher = new EventDispatcher(endPoint, endPointListener); 
			dispatchers.put(endPoint, dispatcher);
		}
		return new EventSinkImpl(types, dispatcher); 
	}

	public EventSource getEventSource(Class type) throws IOException { 
		return getEventSource(new Class[] { type }); 		
	}

	public EventSource getEventSource(Class[] types) throws IOException { 
		return getEventSource(InetAddress.getByName(TypeCastConstants.DEFAULT_EVENT_ADDRESS), TypeCastConstants.DEFAULT_EVENT_PORT, types); 		
	}

	/**
	 * Create a EventSource that can be used to publish event of specific types
	 * 
	 * @param types
	 *            The types that this EventSource should support.
	 * @return
	 */
	public EventSource getEventSource(InetAddress addr, int port, Class[] types) throws IOException { 
		EndPoint endPoint = new EndPoint(addr, port); 
		EventSourceImpl source = new EventSourceImpl(endPoint, types); 
		return source; 
	}
}
